We propose to study how healthy and malnourished infant rats first learn to modify their feeding behavior. The experiments are designed to test exciting new hypotheses about the relationship between associative learning and feeding competence, and to provide an animal-model system for the study of feeding deficiencies in premature and fetal-alcohol infants. We will study offspring of normally-nourished rat dams, undernourished dams, and dams exposed to ethanol-adulterated diets. The first series of experiments examine how dams deliver milk, and how pups differ in their first attempts to suck and swallow it. The second series analyzes how pups might learn to persist in their attempts to suck and swallow milk, and how feeding persistence acquired while suckling might affect the onset of weaning and the persistence of goal-directed responding subsequent to weaning. The third series examines how pups of the three different populations acquire preferences for chemosensory cues during suckling, and how these acquired preferences influence mother-infant "bonding" and subsequent food selection.